一瞬

いっしゅん

a moment, an instant

JLPT N3

Character Breakdown

Meaning and Usage

"一瞬" (いっしゅん) means "a moment" or "an instant," referring to a very short period of time. It is often used to emphasize how quickly something happens or changes.

Common Contexts

You will frequently see "一瞬" used to describe sudden changes in appearance, feelings, or situations, such as a facial expression changing or a quick decision being made.

Collocations and Patterns

  • 一瞬で (いっしゅんで): "in an instant" — used to describe something happening very quickly.
  • 一瞬の判断 (いっしゅんのはんだん): "a moment's decision" — emphasizes the importance of quick thinking.
  • 一瞬も (いっしゅんも): "not even for a moment" — used in negative sentences to stress continuous states.

Register and Nuance

"一瞬" is neutral and can be used in both casual and formal contexts. It often conveys a sense of surprise or suddenness.

Common Mistakes

Learners sometimes confuse "一瞬" with "瞬間" (しゅんかん), which also means "moment" or "instant." While similar, "一瞬" often emphasizes the brevity of time more subjectively, whereas "瞬間" can be more objective or technical. Use "一瞬" when focusing on the fleeting nature of the moment.

Example Sentences

かれのかおがいっしゅんでまっかになった。

His face turned bright red in an instant.

いっしゅんのはんだんがしょうはいをわけることもある。

A moment's decision can sometimes determine victory or defeat.

そのけいけんはいっしゅんできえてしまった。

That scene disappeared in an instant.